Air conditioning system



March 14, 1939. s 1 SHURE 2,150,252

AIR CONDITIONING SYSTEM Filed Oct. 12, 1935 www,

PatentedfMar. 1'4, 1939 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to air conditioning systems and particularly to those installed in store rooms and other public places wherein there is a constant stream of persons through the entrance thereof. This constant opening and closing of the entrance door results in excessive loss of conditioned air from the room, making such systems extremely expensive to operate. Also many. merchants believe that an open entrance has a decided stimulating effect upon business in that it presents a cordial atmosphere and reduces any hesitancy on the part of a possible customer in entering their place of business. Hence many merchants have hesitated to install air conditioning systems for the reason that such systems necessitate a closed entrance door to prevent .oss of the conditioned air as well as entrance of heat from the street. It is therefore, the principal object of the present invention to provide means for retarding escape of conditioned air of a room through an entrance thereto and to exclude the ingress of hot exterior air when the doors are opened and closed or when the doors are purposely left open as a trade stimu- J lant.

It is also a purpose of the present invention to not only retard iiow of conditioned air through an entrance-door but to exclude the entrance of insects, dust and the like, in case of restaurants and places handling food products.

In accomplishing these and other objects of the invention as hereinafter pointed out, I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawing wherein: v

Fig. 1 is a vertical section through an air conditioned store building equipped with the present invention.

Fig. 2 is a longitudinal sectionthrough the entrance of the building, particularly illustrating the duct outlet for inducing the curtain of air used in retarding direct escape of the conditioned air and entrance of dust, dirt or warm exterior air from the street.

Fig. 3 is a modified form of the invention wherein the air is discharged transversely across the door opening.

Referring more in detail to the drawing:

' I designates a building including a store room 2, having a front il facing a street 4, and provided withV an entrance 5, that is ordinarily closed by a `door 6 and through which patrons enter and leave the store.

Located in the basement 1, or other convenient placeY within the building, is an air conditioning unit 8, including a -housing 9, wherein air is conditioned as to temperature, moisture and purity, for delivery to the store room under the propelling influence of a blower I0 connected to the outlet end II of the housing, and discharging into a delivery duct I2 that conducts the air into the room. T'he duct I2 preferably extends upwardly within the store room back of a partition wall I3, and discharges through a grill I4, located at a point adjacent the ceiling I5.

After circulating through the room the air is returned to the conditioning unit through a grill I6, that is shown as being located at the opposite side of the room, and which forms an inlet to a return duct II, leading to the inlet end I8 15 of the housing 9. l

It is thus apparent that the conditioned v'air is constantly circulated through the store room to maintain'a conditioned atmosphere therein. However, in order to maintain purity of the air, it is necessary to provide for a supply of fresh air and to allow for escape of a corresponding portion of the used air.

In the illustrated instance, the fresh air suppl is admitted from the exterior of the building through an intake duct I9 that discharges in'to the r'eturn duct I1 as at 20, under the control of a damper 2| that may be set to admit the desired amount of fresh air into the return duct under the suction of the blower II). Ordinarily the excess air in the room 2 exhausts through the various cracks and crevices around the door and window openings proportionately to the new supply of air drawn through the intake duct I9.

Ordinarily in a system of this character it is necessary that the door 6 be closed in order to prevent the entrance of warm air from the street 4, and to prevent excessive escape of the conditioned air from within the building. However, when door 6 is frequently opened and closed, the loss of the conditioned air is such as to render the operation of the system extremely expensive and in cases where the merchant desires'that the door 6 remain open for the reason above noted, the flow of conditioned airthrough the door seriously interferes with the successful operation of the conditioning system and renders it extremely expensive to operate.

I have found that by discharging a curtain of air across the door opening at 'a sufliciently high 50 velocity so that the pressure thereof is greater than the pressure of atmosphere within thev room, the direct escape of conditioned air is reduced. The curtain of air also prevents the inow of warm air from the streetsince I direct the flow of curtaining air so that it is discharged downwardly and slightly outwardly through the door opening, thereby effecting a positive flow therethrough in the direction of the street. In most instances the volume of air required to maintain the desired curtaining effect is no more than that ordinarily exhausted from the building in 'compensating for the additional fresh air drawn through the supply duct. I, therefore, provide for obtainingythe supply of air to form the curtain from air within the room, or from the return duct wherethrough the air is returned to the conditioning unit, as now to be described.

Located at one edge of the door, for example at the header 22 thereof, is a discharge duct 23 having a grill opening 2t extending in horizontal relation across the top of the door preferably in downwardly facing relation as best illustrated in Fig, 2. The opposite end of the duct extends to the side of the building remote from the inlet of the conditioned air which is provided with an inlet 25, through which air is drawn by means of a fan 26 that is located within the duct. The inlet 25 is preferably provided with a series of louvers 21 so arranged as to selectively close oi the inlet opening and regulate the amount of air drawn from the room.

I have also provided for selectively drawing a vportion of the curtaining air through a lateral duct 23, connecting with the duct 23 as at 29, so

that if desired the louvers 27 may be adjusted and all or part of the air drawn from the lateral duct 28. The duct 28 is provided with a damper 30 so as to control the amount of air drawn therethrough. In this instance the grill I6 is 'of suicient capacity to adequately supply both ducts. In order to direct the air in a slightly outward direction and assure its escape at the bottom ofthe door, the discharge opening of the duct 23 is provided with bames 3l which may be adjusted to direct the curtain of air at the desired angle, as shown in Fig. 2. The louvers 2T and the damper 30 may be so adjusted that the amount of air discharged over the door is substantially equal to the amount of fresh air necessary in maintaining purity of the air in the TOOm.

In Fig. 3, conduit 32 is arranged for discharging v the cui-taining air transversely acrossthe door opening 33, to accomplish the same results.

In operating a system-constructed and assembled as described,`and assuming the door t is left lopen, the conditioned air is discharged through vthe damper 2l for maintaining purity 'of the air being circulated through the conditioned unit.

The damper 30 and the louvers 2l are so adjusted that the amount-ofairdrawn from' the return ductox` from the room through the grill 25 in maintaining the curtaining effect, is sub- "stantially equal to the amount of air admitted through the duct' iS "Ihecurtaining air drawn -from the`room or from the return duct' is discharged underthe fpropelling `forc'e of the ian 26 through the grill Zly under suciently high AVelocity topmaintain la curtain: of* air` moving across the door opening as'shown by the-arrows 'in Fig.V 2, 'the iiow of air beingof: `suchvelocity as to substantially retard direct loss of the freshly conditioned air vthrough the door and to vprevent entranceof the warmlair from the street.

In the case of restaurants or other` places of business handling food products, the curtain of air also has the additional advantage in that it prevents the entrance of insects, dust and the like. i

lIf it is desired to keep the door 6 closed, the discharge of the curtain of air thereacross increases the efficiency of the conditioning system because. it substantially retards direct escape of the conditioned air through the door when the door is opened and closedrincidental to the entrance and exit of persons into and from the room.

From the foregoing it is apparent that I have provided a simple, effective means for retarding direct loss of the freshly conditioned air and that the air employed in retarding the loss is substantially that which would ordinarily be discharged from the room in order to allow the entrance of additional fresh air in maintaining purity of the air conditions in the building.

What I claim and desire to secure by Letters Patent is:

l. In a building having an air conditioned space and an entrance to said space, an air conditioning unit, delivery and return ducts for conducting a stream of air from said space through said unit and back to said space, an air-duct connected with the return duct and having an outletcoextensive with one edge of the entrance, and a fan connected with said air duct for withdrawing air from the return d uct for delivering the air through said air duct for discharge across said entrance in curtain-like formation.

2. In a building having an'air conditioned space and an entrance to said space, an air duct having an outlet coextensive with the top of the entrance, a fan connected with said duct and having its inlet in communication with the air conditioned space for withdrawing air from said space and delivering the air through said duct for discharge downwardly across said entrance to the exterior of said air conditioned space in curtain-like formation, and baiiies in said outlet for directingsaid curtain-like formation of air y to the exterior of the air conditioned space.

3. In a building having anvair conditioned space and an entrance to said space, an air conditioning unit, means for supplying fresh air to said unit from theexterior of said space, means for circulating a stream of air from said space through said unit and back to said space, means for withdrawing air from said space and discharging said withdrawn air in curtain-like formation completely covering said entrance for discharge to the exterior of the air conditioned space, means for regulating said withdrawn air supply, and means `for regulating said fresh air supply proportionately to the withdrawn air.

l 4. In a building having an air conditioned space vand any entrance vto said space, an air conditioning'unitpmearisforzcirculating a stream of l air from said spaceV throughsaid unit and backto said'spaCe, anfair duct havingan outlet coextensive with one edge of the entrance, a fan connecting said duct and having its inlet open lto thecirculated airior withdrawing a part of said circulated air and delivering said withdrawn air through the duct for discharge'in*curtain-like formation completely'covering said entrance, and Lm'eansfinf said outlet for directing the curtain of -ai-r at an' angle Lthroughthe entrance.: f

I SAMUEL QI. 

